SLU news

Feeding competition from smaller deer may cause moose to increase pine browsing

Published: 09 December 2019
Moose grazing. Photo.

Forest damage due to moose browsing on economically valuable pine is a well-known problem. Promoting the growth of ericaceous shrubs like bilberry and managing the numbers of smaller deer could be part of the solution.

In areas with high densities of smaller deer such as roe deer, red and fallow deer, moose consume more pine and less ericaceous shrubs. The same pattern is not observed among the smaller deer.

- Feeding competition from the smaller deer over dwarf shrubs may prompt moose to increase feeding on pine which could lead to higher levels of browsing damage says Robert Spitzer, a PhD student at the Department of Wildlife, Fish, and Environmental Studies at SLU.

For his thesis, Robert Spitzer used DNA analysis on thousands of dung samples to investigate what moose, roe deer, red deer, and fallow deer eat throughout the year in different landscapes in Sweden and how they influence each other through their food choices.

The results show that ericaceous shrubs, such as bilberry and lingon are important food sources for all four deer species throughout the year. Moose diets contained higher proportions of pine during the winter and spring compared to the other deer species.

- In order to reduce pine damage, promoting the growth of ericaceous shrubs in forest stands and managing the numbers of the smaller deer species may be of equal or greater importance than simply reducing the number of moose, says Robert Spitzer.

Robert Spitzer will defend his thesis on Friday, December 13, at SLU in Umeå. The research was conducted as part of the Beyond Moose (Inte bara älg) project with support from the Swedish Environmental Protection Agency, the Kempe Foundation, the Västerbotten County Administration Board and the Swedish Association for Hunting and Wildlife Management.